Skip to main content
Pure Technical Services

How To: Setup NVMe-RDMA with VMware

Currently viewing public documentation. Please login to access the full scope of documentation.


With the initial release of vSphere 7.0, Pure Storage's HTML-5 vCenter plugin will not be fully integrated with NVMe-oF functionality. One of the integrations not yet available is setting up the vSphere environment automatically (like we do with iSCSI). This KB is meant to serve as a guide for how to manually setup your environment.

NOTE: This guide is specific to Pure Storage and vSphere setup; this guide will NOT include setting up the switched fabric. 

Configuring the vSphere Environment

Configuration of RDMA NICs on ESXi

Mellanox RDMA NICs

If the ESXi hosts are utilizing Mellanox adapters for NVMe-oF connectivity and the driver is nmlx4_core, you must enable RoCEv2 as the default operating mode is RoCEv1 for this particular driver.

In order to determine which driver your Mellanox adapters are using, look under the "Driver" section when running the following command on the ESXi host(s):

[root@barney:~] esxcfg-nics -l |grep -E 'Name|Mellanox'
Name    PCI          Driver      Link Speed      Duplex MAC Address       MTU    Description
vmnic4  0000:42:00.0 nmlx5_core  Up   25000Mbps  Full   ec:0d:9a:82:5a:32 9000   Mellanox Technologies ConnectX-4 Lx EN NIC; 25GbE; dual-port SFP28; (MCX4121A-ACA)
vmnic5  0000:42:00.1 nmlx5_core  Up   25000Mbps  Full   ec:0d:9a:82:5a:33 9000   Mellanox Technologies ConnectX-4 Lx EN NIC; 25GbE; dual-port SFP28; (MCX4121A-ACA)

We can confirm in the above example that the Mellanox adapter is utilizing the nmlx5_core driver.

The steps below are only applicable to the nmlx4_core driver. No action is required if the Mellanox adapter is using the nmlx5_core driver.

1. Run the following SSH command on all the ESXi hosts that will be connected via NVMe-RDMA:

esxcli system module parameters set -p enable_rocev2=1 -m nmlx4_core

2. Reboot the host.

Once the host has been rebooted you are able to confirm the change has taken affect by running the following command:

[root@barney:~] esxcli system module parameters list --module=nmlx4_core |grep -E 'Name|enable_rocev2'
 Name                    Type  Value  Description
 enable_rocev2           int   1      Enable RoCEv2 mode for all devices
Broadcom RDMA NICs

The following steps must be taken for all Broadcom RDMA adapters.

1. Ensure that the (NIC + RDMA mode) is enabled for the RDMA NICs on the "Device Configuration" page in the BIOS of the host.

Refer to the vendor documentation on how to enter BIOS and modify this value.

2. Once you have confirmed NIC + RDMA mode is abled, run the following commands on the ESXi hosts to enable RoCEv2:

esxcli system module parameters set -m bnxtnet -p disable_roce=0
esxcli system module parameters set -m bnxtroce -p disable_rocev2=0

3. Reboot the host.

Again, to verify the settings have taken place, run the following commands:

[root@barney:~] esxcli system module parameters list --module=bnxtnet |grep -E 'Name|disable_roce'
 Name                          Type           Value  Description
 disable_roce                  bool           0      Disable the RoCE support. 0: enable RoCE support, 1: disable RoCE support. [Default: 1]
[root@barney:~] esxcli system module parameters list --module=bnxtroce |grep -E 'Name|disable_rocev2'
 Name            Type  Value  Description
 disable_rocev2  bool  0      set to 1 to disable ROCEv2 support, set to 0 to enable RoCEv2 support (default)

Creation of vSwitches, port groups, and vmkernel ports:

Once you have enabled the appropriate configuration on your physical RDMA NICs (if applicable), the next step is to configure the vSwitches, port groups, and vmkernel ports on the ESXi hosts. If you have set up iSCSI previously you will notice that it is a very similar setup and configuration process.

The below configuration is only one option (using standard vSwitches). If you would like to use a vSphere Distributed Switches (vDS) then that is also an acceptable configuration option as well.

The important points to consider when setting up your environment:

- At least 2 different port groups are required. (You may have up to 4)
- Each port group should have only 1 physical RDMA NIC port in the "Active adapters" section. The other adapter port(s) should be in the "Unused adapters" section.
- Ensure MTU is configured consistently between the vmkernel adapters and the virtual switch.

Example setup configuration for standard vSwitches:

1. Select the desired ESXi host, select the "Configure" tab, locate the "Networking" section, and select "Virtual switches".

Once you are on the "Virtual switches" page, select "Add Networking".


2. Select "VMkernel Network Adapter".

Screen Shot 2020-03-04 at 12.01.11 PM.png

3. Select "New standard switch" and input the desired MTU size.

Screen Shot 2020-03-04 at 12.01.28 PM.png

4. Add one of the desired Physical NIC ports to the "Active Adapters" leaving the "Standby" and "Unused" adapters empty.

Screen Shot 2020-03-04 at 12.01.40 PM.png

5. Input the desired name of your Port Group "Network label" and any other applicable settings. Ensure you leave all of the "Enabled services" unchecked.

Screen Shot 2020-03-04 at 12.02.01 PM.png

6. Input the desired IP address and subnet mask for the vmknic.

Screen Shot 2020-03-04 at 12.02.21 PM.png

7. Review all of the listed fields and ensure the configuration is correct, then "Finish" the setup.

Screen Shot 2020-03-04 at 12.02.30 PM.png

Step 8: Repeat steps 1 - 7 for the other vSwitch, port group, and vmkernel port.

Creation and Configuration of VMware Software NVMe-RDMA Storage Adapters

After each ESXi host is properly configured and setup with network connectivity the next step is to create the Software NVMe-RDMA Storage Adapters. 

It is important to point out at that you will add at least two "Software NVMe over RDMA adapters" to each ESXi host. This is better outlined in Step #2 below.

1. Select the desired ESXi host, select the "Configure" tab, locate the "Storage" section, and select "Storage Adapters".

Once you are on the "Storage Adapters" page, select "Add Software Adapter".

Screen Shot 2020-03-04 at 1.17.21 PM.png

2. Select "Add software NVMe over RDMA adapter" and choose which "RDMA device" you want to add.

Screen Shot 2020-03-04 at 1.42.02 PM.png

You will repeat this process for all RDMA ports you plan on using.

If you have more than 2 RDMA adapters available, and do not plan on using all of them, you can look at the following ESXi host CLI output to compare which physical ports are associated with each virtual RDMA adapter:

[root@barney:~] esxcli rdma device list
Name     Driver      State    MTU  Speed    Paired Uplink  Description
-------  ----------  ------  ----  -------  -------------  -----------
vmrdma0  nmlx5_rdma  Active  4096  25 Gbps  vmnic4         MT27630 Family  [ConnectX-4 LX]
vmrdma1  nmlx5_rdma  Active  4096  25 Gbps  vmnic5         MT27630 Family  [ConnectX-4 LX]

3. After you have added all applicable Software NVMe-RDMA Storage Adapters the next step is to configure the "Controllers" for every adapter.

You will select the applicable adapter you wish to configure, click on "Controllers" and then select "Add Controller".

Screen Shot 2020-03-04 at 2.01.34 PM.png

4. You can decide to "Automatically discover controllers" or "Enter controller details manually". For simplicity an automatic discovery is recommended otherwise directed by Pure Storage.

Screen Shot 2020-03-04 at 2.43.21 PM.png

You will repeat this process for ALL FlashArray IP addresses dedicated for NVMe-RDMA connectivity. 

Identifying the NVMe Qualified Name (NQN) of an ESXi host

After you have configured your ESXi hosts the next step is recording the NVMe Qualified Name (NQN) of each ESXi host you plan on connecting to the FlashArray. 

[root@barney:~] esxcli nvme info get
   Host NQN:

Until NVMe-oF is implemented into the vSphere API, this is the only known way to get this information. This KB will be updated with a PowerShell and Python example once the API becomes available.


Configuring the FlashArray

Creation of Host & Host Group Objects

From the FlashArray perspective, there isn't going to be much of a difference from setting up iSCSI or FC. If there are questions for setting up hosts and host groups, then you can refer to the FlashArray Configuration KB as that should sufficiently guide you through this process.

As a complimentary addition to that KB, below is an example of adding an NQN to a host object on the FlashArray:
Screen Shot 2020-03-05 at 9.04.50 AM.png